Added support for libc++ standard library (#22)

Added new 'WITH_STDLIB_LIBCXX' CMake option which, when set to
'ON', adds '-stdlib=libc++' compiler/linker flag. This option
exists only when building with a compiler from the 'Clang' family.
'OFF' by default, except for the 'Darwin' platform where it is
'ON'.

GitHub Workflows scripts updated to use '-DWITH_STDLIB_LIBCXX=ON'
for the 'Clang' configurations.

.github/workflows/cmake.yml

@@ -66,13 +66,15 @@ jobs:
             build_type: "Debug",
             cc: "clang-16",
             cxx: "clang++-16",
+            libcxx_cmake_flags: "-DWITH_STDLIB_LIBCXX=ON",
             label: "debug_clang16"
           }
         - {
             name: "Clang 16 RelWithDebInfo",
             build_type: "RelWithDebInfo",
             cc: "clang-16",
             cxx: "clang++-16",
+            libcxx_cmake_flags: "-DWITH_STDLIB_LIBCXX=ON",
             label: "relwithdebinfo_clang16"
           }
 
@@ -92,7 +94,7 @@ jobs:
         wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
         echo deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-16 main | sudo tee /etc/apt/sources.list.d/llvm.list
         sudo apt-get update
-        sudo apt-get install clang-16 lld-16 clang-tidy-16
+        sudo apt-get install clang-16 lld-16 clang-tidy-16 libc++-16-dev libc++1-16 libc++abi-16-dev libc++abi1-16
 
     - name: Info CC compiler
       run: ${{matrix.config.cc}} --version
@@ -130,6 +132,7 @@ jobs:
           -DCMAKE_BUILD_TYPE=${{matrix.config.build_type}}  \
           -DCMAKE_C_COMPILER=${{matrix.config.cc}} \
           -DCMAKE_CXX_COMPILER=${{matrix.config.cxx}} \
+          ${{matrix.config.libcxx_cmake_flags}} \
           -DBOOST_ROOT=${{runner.temp}}/deps/${{format('boost_{0}_{1}_{2}', env.BOOST_MAJOR, env.BOOST_MINOR, env.BOOST_PATCH)}} \
           -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
 

CMakeLists.txt

@@ -21,6 +21,29 @@ target_compile_options(binlog_server_compiler_flags INTERFACE
   "$<${msvc_cxx}:$<BUILD_INTERFACE:${msvc_warnings}>>"
 )
 
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+    set(WITH_STDLIB_LIBCXX_DEFAULT ON)
+  else()
+    set(WITH_STDLIB_LIBCXX_DEFAULT OFF)
+  endif()
+  option(WITH_STDLIB_LIBCXX "Use libc++ standard library" ${WITH_STDLIB_LIBCXX_DEFAULT})
+
+  if(WITH_STDLIB_LIBCXX)
+    message(STATUS "Using libc++ standard library")
+    set(libcxx_options "-stdlib=libc++")
+  else()
+    message(STATUS "Using libstdc++ standard library")
+    set(libcxx_options "-stdlib=libstdc++")
+  endif()
+  target_compile_options(binlog_server_compiler_flags INTERFACE
+    "$<${clang_cxx}:$<BUILD_INTERFACE:${libcxx_options}>>"
+  )
+  target_link_options(binlog_server_compiler_flags INTERFACE
+    "$<${clang_cxx}:$<BUILD_INTERFACE:${libcxx_options}>>"
+  )
+endif()
+
 find_package(Boost 1.83.0 EXACT REQUIRED)
 
 find_package(MySQL REQUIRED)